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Well, I can speak to this...
Like you said, decking the cylinder head is going to raise the compression ratio. Therefore, your combustion pressures are going to rise as well. That is a good thing...
Too much of a good thing leads to detonation as you probably know, which is a BAD thing. It will trash your engine if left unchecked.
Higher compression will make your bike run hotter, since the combustion temp is higher. An ignition advancer can do the same thing too. Both of these combined could make your bike run too hot for practical use (commuting) or cause too much detonation on pump gas (octane booster all the time). Plus your spark plugs will fry out sooner.
My guess is you will see a big difference from the head decking, but get a minimal gain if any from the advancer.
The truth is you need to try it with and without the advancer on a dyno (THE SAME DYNO, preferably on the same day, at the same temp, with the same gas) to be sure. Dyno runs are pretty cheap, and they offer a lot of information. If you do not see a big difference on the dyno, or cannot feel the difference, then leave the advancer off IMHO.
OK hope that helps! If Gunther or someone of his knowledge level reads this post I'll bet he will say something similar. If they disagree, well, then they are just being difficult or are clueless /images/icons/wink.gif/images/icons/smile.gif
I am experimentally verifying the Theory of Relativity.
http://home.satx.rr.com/jroberts
Like you said, decking the cylinder head is going to raise the compression ratio. Therefore, your combustion pressures are going to rise as well. That is a good thing...
Too much of a good thing leads to detonation as you probably know, which is a BAD thing. It will trash your engine if left unchecked.
Higher compression will make your bike run hotter, since the combustion temp is higher. An ignition advancer can do the same thing too. Both of these combined could make your bike run too hot for practical use (commuting) or cause too much detonation on pump gas (octane booster all the time). Plus your spark plugs will fry out sooner.
My guess is you will see a big difference from the head decking, but get a minimal gain if any from the advancer.
The truth is you need to try it with and without the advancer on a dyno (THE SAME DYNO, preferably on the same day, at the same temp, with the same gas) to be sure. Dyno runs are pretty cheap, and they offer a lot of information. If you do not see a big difference on the dyno, or cannot feel the difference, then leave the advancer off IMHO.
OK hope that helps! If Gunther or someone of his knowledge level reads this post I'll bet he will say something similar. If they disagree, well, then they are just being difficult or are clueless /images/icons/wink.gif/images/icons/smile.gif
I am experimentally verifying the Theory of Relativity.
http://home.satx.rr.com/jroberts
